Problem: Solve for $x$. Enter the solutions from least to greatest. $4x^2 + 4x - 168 = 0$ $\text{lesser }x = $
$\begin{aligned} 4x^2 + 4x - 168 &= 0 \\\\ 4(x^2+1x-42)&=0 \end{aligned}$ Now let's factor the expression in the parentheses. $x^2+1x-42$ can be factored as $(x+7)(x-6)$. $\begin{aligned} 4(x+7)(x-6)&=0 \\\\ x+7=0&\text{ or }x-6=0 \\\\ x=-7&\text{ or }x=6 \end{aligned}$ In conclusion, $\begin{aligned} \text{lesser }x &= -7 \\\\ \text{greater }x &= 6 \end{aligned}$